Thermostat Replacement The engine needs a new thermostat but I cannot locate it - any clues?

Follow the top radiator hose down to where it connects to the engine. You should find a dome shape item or a couple of smaller bolts that attach to the engine to the side of the radiator hose and the thermostat will be inside the housing. You will need to drain the radiator, remove the bolts holding the thermostat housing to the engine and remove the old stat and put in a new one be sure to make note of how the stat is facing when you remove it and put the new one in the same way. then reconnect the thermostat housing making sure the gasket is in place so it won't leak, then refill the radiator slowly so you don't cause an air lock in the radiator, with cap still off start the engine and allow it to warm up until the stat opens and then you will need to add more antifreeze to the system. Double check for any leaks. Turn on the heater and make sure you have good heat and you should be good

To replace a thermostat in a 2001 Dodge Grand Caravan, look at the engine. Should be located at the engine end of the upper radiator hose in removable housing. Drain about 1 gallon of coolant from radiator Remove housing - make note how thermostat is installed Clean both surfaces Install new thermostat and gasket Re-fill coolant slowly to prevent an "air lock" Start engine check for leaks Run engine to normal operating temperature with heater on Check coolant level.------------------------------------------------------------------------------------------
Best R270 BMW CAS4 BDM Programmer

The exact location of the thermostat varies depending on the particular engine model on your Pontiac Montana. Although 2.0L turbo and non-turbo engines locate the thermostat on the upper section of the engine, other models may follow the lower radiator hose to a lower position on the engine, requiring the removal of one or more components for replacement. see below

• Park your car in a safe place and open the hood.
  
• 2Locate the thermostat housing by following the upper or lower radiator hose from the radiator towards the engine. The end of the hose should be connected to an aluminum or metal housing attached to the engine by two mounting bolts.
  
• 3Remove the air cleaner duct assembly and the crossover exhaust pipe, if necessary, using a wrench and ratchet and socket.
  
• 4Place a drain pan underneath the radiator drain valve. Open the valve and drain some of the coolant to empty the radiator hose; then close the valve.
  
• 5Remove the radiator hose from the thermostat housing by disconnecting the clamp using a pair of rib joint pliers, Phillips screwdriver or ratchet and socket, depending on type of clamp used on your particular model; then remove the hose.
  
• 6Remove the two thermostat housing bolts and lift the housing off the engine. Before removing the thermostat off the engine, pay careful attention to the position of the relief valve on the thermostat in relation to the mounting base on the engine, looking for any special marks. The new thermostat has to be mounted in this same exact position. Also, note that the thermostat spring has to point towards the engine once it is seated on the engine; then remove the thermostat and any gasket material if necessary.
  

Installation

• 1Clean the thermostat housing and engine mounting surfaces from gasket material, if necessary, using a plastic scraper; also, clean the bolt threads of the thermostat housing bolts of sealer, if necessary, using a wire brush.
  
• 2Apply a light coat of Room Temperature Vulcanizing (RTV) sealer to the new paper gasket if your particular model requires one; or install a new O-ring to the center of the thermostat; also, apply a light coat of RTV sealer to the threads of the thermostat housing mounting bolts.
  
• 3Install the new thermostat on the engine mounting base in the same exact position as the old one; install the paper gasket if required and set the thermostat housing in place. Start the housing mounting bolts by hand and then tighten the bolts.
  
• 4Connect the radiator hose to the thermostat housing; then install the crossover exhaust pipe and air cleaner and duct assembly, if necessary. Fill the radiator with new coolant, start the engine and let it reach operating temperature. Check for leaks and add more coolant to the reservoir to bring the level between the Add and Full Hot marks and turn off the engine.
  
• 5Bleed the cooling system if the thermostat housing is provided with a valve screw on it. Once the engine reaches operating temperature, loosen the valve screw until coolant begins to leak through the screw; then tighten the screw again
  

Read more: How to Change a Pontiac Montana Thermostat ' eHow.com http://www.ehow.com/how_4900141_change-pontiac-montana-thermostat.html#ixzz1eRUgRlYC

For 1989 Toyota Truck Land Cruiser 4.0L FI 6cyl, check this diagrams, according with your Engine Code...



Fig. 1: On, 3VZ-E engines the thermostat is located in the waterpump




Fig. 2: Exploded view thermostat and housing on the 1FZ-FE engine




Fig. 3: Exploded view thermostat and housing on the 2RZ-FE and 3RZ-FE engines




Fig. 4: Exploded view thermostat and housing on the 5VZ-FE engine


To install:

1. When installing a new thermostat always use a new gasket. Be sure that the thermostat is positioned with the spring down or into the housing. On 3VZ-E engines, the jiggle valve (looks like a small rivet in the edge of the thermostat) must be at the top or 12 o'clock position.

Fig. 8: If used, the thermostat must be installed with the jiggle valve at the top

1. Install the water inlet. Install the bolts finger-tight until the inlet is positioned exactly. Tighten the bolts to 10-14 ft. lbs. (13-19 Nm). Overtightening will break the ear off the housing and spoil your afternoon-don't do it.
2. Install the hoses and wire connectors removed for access. Make certain the coolant hoses are not kinked or twisted after installation. Do not overtighten the hose clamps.
3. Fill the cooling system with coolant.
4. Start the engine and check for leaks. Top off any fluid levels.

About parts replacement, try to check in THIS SITE: Thermostat Universal

Hope this helps.

follow the top radiator hose to the engine,the hose is connected to the thermostat housing,remove hose clamp and hose,remove two bolts holding housing down,lift up and there is your thermostat,clean the housing and intake gasket material off,install the new thermostat with spring facing down in engine,and reinstall housing and hose and clamp,refill radiator before starting.

I had the same problem a couple of years ago. It is actually located on the bottom of the engine. I have no clue why. They are usually located on the top for easy access. Follow the hose coming from the bottom of the radiator to the engine block.

Most likely the thermostat itself is going bad. When they fail, they get stuck open so that the engine doesn't overheat. Problem is, the coolant doesn't stay in the engine long enough to absorb enough heat to adequately heat the climate control air. You'll most likely need a new thermostat. They're inexpensive to buy (on my Audi it's a $13 part) but depending on where it is located, it could be cheap or expensive for labor.

Explorer Thermostat LocationHere is advice for finding the thermostat:

• Follow the upper radiator hose from the radiator to the engine and there is a housing that houses the thermostat. Take it off and when you reinstall the thermostsat, make sure the spring goes toward the engine.

• The thermostat is located on the motor block under the three bolt flang that the top rediator hose connects to. Remove the three 10MM bolts and the thermostat can be removed for replacement.

How to Change an Explorer Thermostat

• 1. Remove the air cleaner air duct from the throttle body and air cleaner.
• 2. Follow the upper radiator hose to the engine to locate the thermostat housing. The housing is located at the front of the intake manifold.
• 3. Loosen the hose clamp, then detach the hose from the fitting. This can be difficult. If it's stuck, grasp with a pair of adjustable pliers and twist to break the seal. Then pull it off.
• 4. Remove the bolts and detach the housing cover. Be prepared some coolant may leak out as the gasket seal is broken. Remove the thermostat.
• 5. Install the new o-ring onto the thermostat (no gasket is needed) and install the thermostat into the intake manifold with the spring side pointing toward the engine.
• 6. Make sure the air release valve is in the up 12 o'clock position. Install housing cover and bolts. Reattach the hose fitting and tighten the hose clamp. Fill the cooling system with a 50/50 mix of coolant and water, and burp the system.

Most thermostats are located in the upper radiator hose housing mounted to engine block. Make sure engine is cold put a catch pan under your car to catch any antifreeze that comes out. Remove the two bolts holding the housing on the engine and remove thermostat and gasket. Clean engine block where gasket goes very good and also the housing, have to remove all gasket material so when installing new one it will seal and wont cause a leak. Make sure when you put the thermostat back in it goes in spring side down towards engine. Replace housing and bolts. replace lost coolant with a 50/50 mixture in your recovery tank. Start engine let heat to temp and check for leaks.

The 2.7L engine lower radiator hose, connects to the thermostat housing.

To Remove:
1.Disconnect the Negative battery cable.
(Engine COLD!)

1. Drain cooling system.
2. Remove radiator lower hose from thermostat housing.
3. Remove nuts from heater tube flange studs.
4. Loosen starter bolt at heater tube bracket.
5. Pull heater tube out of thermostat housing and position out of the way.
6. Remove bolt and two studs.
7. Remove thermostat housing, O-ring and thermostat.
8. Remove thermostat housing bolts.

To install:
A.Clean gasket sealing surfaces.
B.Install thermostat with the bleed valve located at the 12 o'clock position, between tabs on seal.

1. Install thermostat and seal into thermostat housing .
2. If removed, install two studs.
3. Install thermostat, thermostat housing and O-ring and bolt. Tighten attaching bolts to 105 inch lbs.(12 Nm).
4. Lubricate new heater return tube O-ring with coolant.
5. Position heater return tube flange over two studs. Install nuts.
6. Tighten retaining nuts to 53 inch lbs.(6 Nm).
7. Tighten starter bolt to 40 ft. lbs. (54.3 Nm).
8. Connect the lower radiator hose to the thermostat housing. Install hose clamps.
9. Refill cooling system.
10. Inspect for leaks.
11. Connect negative cable.

3.2 and 3.5L engines:
Disconnect the battery cable. (Again engine COLD)

1. Drain cooling system.
2. Raise vehicle on hoist.
3. Disconnect electrical connectors from engine oil and power steering pressure switches.
4. Disconnect radiator and heater hoses from thermostat housing.
5. Remove thermostat housing bolts.
6. Remove housing, thermostat, and gasket.

The OEM thermostat is staked in place at the factory. To ensure proper seating of replacement thermostat, carefully remove the bulged metal from the thermostat housing, using a suitable hand held grinder. It is not necessary to restake the replacement thermostat, into the thermostat housing.

To Install:

1. Position gasket on thermostat and housing.
2. Install thermostat housing, gasket and mounting bolts onto block. Tighten attaching bolts to 105 inch lbs. (12 Nm).
3. Install radiator hose.
4. Install bypass hose.
5. Connect electrical connectors from engine oil and power steering pressure switches.
6. Connect negative cable.
7. Fill cooling system.
8. Inspect for leaks.
9. Lower vehicle on hoist.

From AutoZone Repair Guides

I feel this way, I can give you an accurate description, and have taken into account your safety.